Method for transmitting control signal

ABSTRACT

There is provided a method of enabling a user equipment to transmit a control signal to a base station. The method includes allocating a control signal to a control region on a subframe, the subframe comprising the control region for the control signal and a data region for user data, wherein different frequency bands within the control region are allocated to different user equipments, and transmitting the subframe in uplink direction. A control signal can be robustly transmitted under variance of channel condition.

TECHNICAL FIELD

The present invention relates wireless communications, and moreparticularly, to a method of transmitting a control signal in a wirelesscommunication system.

BACKGROUND ART

A third Generation Partnership Project (3GPP) mobile communicationsystem based on a Wideband Code Division Multiple Access (WCDMA) radioaccess technology has widely deployed all over the world. High SpeedDownlink Packet Access (HSDPA), which can be defined as the firstevolution stage of the WCDMA, provides the 3GPP mobile communicationsystem with high competitiveness in the mid-term future. However, sincethe requirements and expectations of users and service providerscontinuously increase and the development of a competing radio accesstechnology is in progress, there is a need for a new technologyevolution in the 3GPP for further competitiveness.

One of systems that are considered in the post third-generation systemsis an Orthogonal Frequency Division Multiplexing (OFDM) system which canattenuate an Inter-Symbol Interference (ISI) with low complexity. In theOFDM system, pieces of data that are input in series are transformedinto N pieces of parallel data and then transmitted through Nsubcarriers. The subcarriers have orthogonality with each other.Orthogonal Frequency Division Multiple Access (OFDMA) refers to amultiple access scheme of realizing multiple access by independentlyproviding each user with part of subcarriers.

One of the major problems of the OFDM/OFDMA system lies in thatPeak-to-Average Power Ratio (PAPR) can be very high. The PAPR problem isthat the peak amplitude of a transmit signal is very higher than a meanamplitude. It has its origin in that an OFDM symbol is constructed byoverlapping N sinusoidal signals on different subcarriers. The PAPR isrelated to the capacity of the battery and problematic in user equipmentsensitive to power consumption. To reduce power consumption, it isnecessary to lower the PAPR.

One of systems that have been proposed to lower the PAPR is SingleCarrier-Frequency Division Multiple Access (SC-FDMA). The SC-FDMA is ofa type in which Frequency Division Multiple Access (FDMA) is combinedwith a Single Carrier-Frequency Division Equalization (SC-FDE). TheSC-FDMA has a similar characteristic to that of OFDMA in that data ismodulated and demodulated in time domain and frequency domain byemploying Discrete Fourier Transform (DFT), but is advantageous intransmission power saving because the PAPR of a transmit signal can belowered. In particular, it can be said that SC-FDMA is advantageous inuplink direction in which communication is performed from a userequipment to a base station, which is sensitive to transmission power inrelation to the battery capacity of the user equipment.

Important things when the user equipment transmits data to the basestation are small bandwidth and wide coverage. The SC-FDMA system haswider coverage than that of other system when using the same poweramplifier is provided.

Data includes user data and a control signal concerned with the userdata. A transmitter can transmit only the control signal and can alsotransmit the user data and the control signal by multiplexing them. Iftransmission of the control signal is failed, a receiver does not knoweven whether user data has been sent. Accordingly, transmission of thecontrol signal requires high reliability.

Since radio resources used for transmitting the control signal may limitdata rate, it is better that radio resources necessary for transmittingthe control signal are small. Also, a number of terminals exist withinone cell. It is therefore necessary for a base station to identify auser equipment which has sent the control signal.

There is a need for a method of allowing a user equipment to transmit acontrol signal to a base station with high reliability.

DISCLOSURE OF INVENTION Technical Problem

An object of the present invention is to provide a method oftransmitting a control signal in uplink direction.

Another object of the present invention is to provide a method ofmultiplexing of a control signal and user data.

Technical Solution

In one aspect, there is provided a method of enabling a user equipmentto transmit a control signal to a base station. The method includesallocating a control signal to a control region on a subframe, thesubframe comprising the control region for the control signal and a dataregion for user data, wherein different frequency bands within thecontrol region are allocated to different user equipments, andtransmitting the subframe in uplink direction.

In another aspect, a method includes allocating a control signal to adata region on a subframe by multiplexing the control signal and userdata, the subframe comprising a control region only for transmitting thecontrol signal and the data region and transmitting the subframe inuplink direction.

ADVANTAGEOUS EFFECTS

A control signal can be robustly transmitted under variance of channelcondition. Both a control signal and user data can be transmittedefficiently under limited radio resources through multiplexing of thecontrol signal and the user data.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view illustrating a wireless communication system.

FIG. 2 is a block diagram of a transmitter according to an embodiment ofthe present invention.

FIG. 3 is a block diagram of a SC-FDMA modulation unit.

FIG. 4 is a block diagram of a receiver according to an embodiment ofthe present invention.

FIG. 5 illustrates an example of a radio frame.

FIG. 6 illustrates an example of a subframe.

FIG. 7 illustrates a control channel format employing FDM method.

FIG. 8 illustrates an example of a control channel.

FIG. 9 illustrates another example of a control channel.

FIG. 10 illustrates still another example of a control channel.

FIG. 11 illustrates still another example of a control channel.

FIG. 12 illustrates a control channel format employing CDM method.

FIG. 13 illustrates an example of a frequency hopping pattern on asubframe.

FIG. 14 is a block diagram illustrates an example in which user data andthe control signal are multiplexed.

FIG. 15 is a block diagram illustrates another example in which userdata and a control signal are multiplexed.

FIG. 16 illustrates an example in which a control signal is allocated toa control region.

FIG. 17 illustrates an example in which a control signal is allocated toa data region.

FIG. 18 illustrates an example in which a control signal and user dataare time-division multiplexed.

FIG. 19 illustrates multiplexing of a control signal and user datathrough multiplication operation.

FIG. 20 illustrates multiplexing of a control signal and user datathrough addition operation.

MODE FOR THE INVENTION

FIG. 1 is a view illustrating a wireless communication system. Thewireless communication system is disposed in order to provide a varietyof communication services such as voice and packet data.

Referring to FIG. 1, a wireless communication system includes a userequipment (UE) 10 and a base station (BE) 20. The user equipment 10 canbe fixed or mobile and may also be called other terms such as a MobileStation (MS), a User Terminal (UT), a Subscriber Station (SS) and awireless device. The base station 20 generally refers to a fixed stationthat communicates with the user equipment 10 and may also be calledother terms such as a node-B, a Base Transceiver System (BTS) and anaccess point. One or more cells may exist in one base station 20.

Hereinafter, downlink refers to communication from the base station 20to the user equipment 10, and uplink refers to communication from theuser equipment 10 to the base station 20. In downlink direction, atransmitter can be part of the base station 20 and a receiver can bepart of the user equipment 10. In uplink direction, a transmitter can bea part of the user equipment 10 and a receiver can be a part of the basestation 20.

Multiple access schemes for downlink and uplink transmission may differ.For example, downlink transmission may use OFDMA and uplink transmissionmay use SC-FDMA.

FIG. 2 is a block diagram of a transmitter according to an embodiment ofthe present invention.

Referring to FIG. 2, the transmitter 100 includes a data processing unit110, a SC-FDMA modulation unit 120, a control unit 130, a RadioFrequency (RF) unit 140 and a transmit antenna 150.

The data processing unit 110 converts input information bit into a datasymbol. The data processing unit 110 performs channel-coding andconstellation-mapping the information bit and outputs the data symbol.The information bit includes user data to be sent to a receiver. Theinformation bit may also include a control signal related totransmission of user data or allocation of radio resources.

The SC-FDMA modulation unit 120 modulates the data symbol using aSC-FDMA modulation method. The control signal can be modulatedseparately from the user data and then input to the SC-FDMA modulationunit 120. The SC-FDMA modulation unit 120 spreads the data symbolthrough Discrete Fourier Transform (DFT) and then performs Inverse FastFourier Transform (IFFT) on the DFT-performed data symbol.

The control unit 130 controls the operations of the data processing unit110 and the SC-FDMA modulation unit 120. The RF unit 140 converts aninput symbol into a radio signal. The radio signal is transmittedthrough the transmit antenna 150.

FIG. 3 is a block diagram of the SC-FDMA modulation unit.

Referring to FIG. 3, a SC-FDMA modulation unit 120 includes a DFT unit121 that performs DFT, a subcarrier mapper 122 and an IFFT unit 123 thatperforms IFFT.

The DFT unit 121 performs DFT on an input data and outputs a frequencydomain symbol. The data input to the DFT unit 121 may include a controlsignal and/or user data. The subcarrier mapper 122 allocates the inputsignal to each subcarrier according to various mapping methods. The IFFTunit 123 performs IFFT on the input symbol and outputs a transmit (Tx)signal. The transmit signal is a time domain signal. The time domainsymbol output through the IFFT unit 123 is called an OFDM symbol.Alternatively, the time domain symbol output through the IFFT unit 123is also called a SC-FDMA symbol because the OFDM symbol undergoes DFTbefore undergoing IFFT.

A method of modulating by combining DFT and IFFT is called SC-FDMA. Thismethod is advantageous in that it can lower the PAPR when compared withOFDM. This is because it has characteristics of a single carrier.

FIG. 4 is a block diagram of the receiver according to an embodiment ofthe present invention.

Referring to FIG. 4, a receiver 200 includes a RF unit 210, a SC-FDMAdemodulation unit 220, a data processing unit 230 and a control unit240.

The RF unit 210 converts a signal, received from a receiver antenna 250,into a digitalized signal. The SC-FDMA demodulation unit 220 performsreverse-operation corresponding to the SC-FDMA modulation unit 120 inthe digitalized signal, and outputs a data symbol. The data processingunit 230 recovers an information bit from the data symbol. The controlunit 240 controls the processing process of the SC-FDMA demodulationunit 220 and the data processing unit 230.

FIG. 5 illustrates an example of a radio frame.

Referring to FIG. 5, a radio frame is comprised of 10 subframes. Thesubframe is a unit for allocating radio resources. One subframe mayinclude two slots. One slot may include a plurality of OFDM symbols. Oneslot may include 7 or 6 OFDM symbols.

The format of the radio frame is only illustrative. The number ofsubframes included in the radio frame, the number of the slots includedin the subframe, and the number of the OFDM symbols included in the slotcan be changed in various ways.

FIG. 6 illustrates an example of a subframe. It may represent an uplinksubframe.

Referring to FIG. 6, a subframe can be divided into two parts of acontrol region and a data region. The control region is a region inwhich only a control signal is transmitted and is allocated to a controlchannel. The data region is a region in which data is transmitted and isallocated to a data channel. The control channel is a channel fortransmitting a control signal, and the data channel is a channel fortransmitting the user data, or the user data and the control signal. Thecontrol channel and the data channel can be comprised of one subframe.The control signal may include various kinds of signals, such asAcknowledgement (ACK)/Negative-Acknowledgement (NACK) signals, a ChannelQuality Indicator (CQI), a Precoding Matrix Index (PMI) and a RankIndicator (RI), not user data.

Only the control signal is transmitted through the control region, butboth the user data and the control signal can be transmitted through thedata region. In other words, when a user equipment transmits only thecontrol signal, the control region is allocated. When a user equipmenttransmits both the user data and the control signal, the data region canbe allocated. As an exceptional case, when the amount of a controlsignal is great or a control signal is inappropriate for transmissionthrough the control region, the data region can be allocated to thecontrol signal.

Since the control region and the data region use different frequencybands, it may be called FDM (Frequency Division Multiplexing). Thecontrol region is positioned on both edges of system bandwidth and thedata region is positioned at the center of the system bandwidth.However, this is only illustrative, and the control region and the dataregion on the subframe are not limited to the above positions. Thepositions of the control region and the data region can be changed andnot limited to the form shown in the drawing.

In view of one user equipment, every slot per one subframe can bedivided into two parts in the frequency domain. Assuming that onesubframe consists of a first slot and a second slot, the first slot canbe divided into a first region and a second region in the frequencydomain, and the second slot may also be divided into a first region anda second region in the frequency domain. Assuming that a control signalis transmitted through the first region of the first slot and user datais transmitted through the second region of the first slot, the controlsignal is transmitted through the first region of the second slot andthe user data is transmitted through the second region of the firstslot. Although both the first region and the second region can beallocated to the control signal, one user equipment does not use sameresource regions over two slots.

A slot allocated to each user equipment may use frequency hopping on asubframe. That is, one of two slots included in one subframe can beallocated to a frequency band on one side and the other of the two slotscan be allocated to a frequency band on the other side so that they arejuxtaposed. Since a control channel for the user equipment istransmitted through slots allocated to different frequency bands,frequency diversity gain can be obtained.

When a plurality of user equipments exist within a cell, a base stationmust send downlink control signals to the plurality of user equipmentsand each user equipment must send an uplink control signal to the basestation. In order to transmit the uplink control signal, radio resourcesmust be allocated every user equipment. For clarify, only uplinktransmission in which the user equipment transmits the control signal tothe base station is below described as an example.

<Transmission of a Control Signal>

When only a control signal is transmitted, the control signal istransmitted through the control region allocated to each user equipment.After a specific radio resource (that is, the control region) isallocated, a user equipment sends the control signal through thespecific radio resource. A channel allocated to the control region inorder to transmit the control signal is called a control channel.

On the control channel, user equipments can be identified by using CodeDivision Multiplexing (CDM) employing inter-code orthogonality orFrequency Division Multiplexing (FDM) employing inter-frequencyorthogonality. The control signal can be transmitted through directmodulation or sequence mapping.

FIG. 7 illustrates a control channel format employing a FDM (FrequencyDivision Multiplexing) method.

Referring to FIG. 7, a plurality of user equipments uses controlchannels allocated to different frequency bands on the control region inorder to send its control signal. The control region is divided into aplurality of frequency bands and a frequency band is allocated to thecontrol channel for each user equipment. For an example, when thecontrol region is divided into N frequency bands, 2N control channelsare allocated to 2N user equipments.

Although the control channel is allocated to one of two control regions,the control channel may be allocated over two control regions so as toobtain diversity gain.

FIG. 8 illustrates an example of a control channel.

Referring to FIG. 8, a control signal is directly modulated on a controlchannel. Assuming that eight OFDM symbols constitute one slot, thecontrol signal is allocated to six OFDM symbols and reference signalsare allocated to the remaining two OFDM symbols. The reference signal isa signal previously known to both a transmitter and a receiver, and isused for channel estimation or data demodulation. The length of the twoOFDM symbols to which the reference signal is allocated (indicated byoblique lines) may be shorter than that of the OFDM symbol to which thecontrol signal is allocated.

The number of the OFDM symbols included in one slot is onlyillustrative, but not limited to. Also, the number of the OFDM symbolsto which the reference signal is allocated or the position of the OFDMsymbol to which the reference signal is allocated is illustrative.

FIG. 9 illustrates another example of a control channel.

Referring to FIG. 9, a control signal and reference signals aremultiplexed on an OFDM symbol. The reference signals and the controlsignal may be arbitrarily multiplexed in a plurality of subcarriersconstituting the OFDM symbol.

FIG. 10 illustrates still another example of a control channel.

Referring to FIG. 10, a control signal is mapped to a sequence and thenallocated to a control channel. The sequence corresponding to thecontrol signal is allocated to the control channel. For example, thesequence may be a Constant Amplitude Zero Auto-Correlation (CAZAC)sequence, a Hardamard sequence, a Walsh code or Golay sequence. Thesequence has good self-correlation characteristic. When the number ofsubcarriers is sufficiently large, cell coverage can be increase byemploying the CAZAC sequence.

In a Zadoff-Chu (ZC) sequence, which is one of CAZAC sequences, a k-thelement P(k) of ZC sequence having a root index M can be represented asshown

$\begin{matrix}{{{P(k)} = {\exp \left\{ {- \frac{j\; \pi \; {{Mk}\left( {k + 1} \right)}}{N}} \right\} \mspace{14mu} {for}\mspace{14mu} N\mspace{14mu} {odd}}}{{P(k)} = {\exp \left\{ {- \frac{j\; \pi \; {Mk}^{2}}{N}} \right\} \mspace{14mu} {for}\mspace{14mu} N\mspace{14mu} {even}}}} & {{MathFigure}\mspace{14mu} 1}\end{matrix}$

where N is the length of the ZC sequence and the root index M is apositive number smaller than N. The root index M is relatively prime toN.

The ZC sequence P(k) has the following three characteristics.

$\begin{matrix}{{{{P(k)}} = {1\mspace{14mu} {for}\mspace{14mu} k}},N,M} & {{MathFigure}\mspace{14mu} 2} \\{{R_{M;N}(d)} = \left\{ \begin{matrix}{1,} & {{{for}\mspace{14mu} d} = 0} \\{0,} & {{{for}\mspace{14mu} d} \neq 0}\end{matrix} \right.} & {{MathFigure}\mspace{14mu} 3} \\{{R_{M_{1},{M_{2};N}}(d)} = {{const}\mspace{14mu} {for}\mspace{14mu} {all}\mspace{14mu} M_{1,}M_{2}}} & {{MathFigure}\mspace{14mu} 4}\end{matrix}$

Equation 2 means that the magnitude of the ZC sequence is always 1.Equation 3 means that auto correlation of the ZC sequence is representedas Dirac-delta function. Auto correlation is based on circularcorrelation. Equation 4 means that cross correlation is always constant.

The ZC sequence may be generated in time domain or frequency domain.IFFT may be performed in order to transform frequency domain ZC sequencethe time domain ZC sequence.

The CAZAC sequence has orthogonality when it has a different root indexor different cyclic shift on the same root index. Thus, various controlsignals may be allocated to the control channel by differentiating aroot index or a cyclic shift. Alternatively, inter-user equipment orinter-cell control channel can be determined by differentiating an indexor performing cyclic shift.

FIG. 11 illustrates still another example of a control channel.

Referring to FIG. 11, one CAZAC sequence is allocated to allocatedresources without matching length of the CAZAC sequence to OFDM symbols.For example, the CAZAC sequence can be allocated to one slot.

When the length of the CAZAC sequence is matched with the OFDM symbols,the number of CAZAC sequences can be reduced and correlation betweenCAZAC sequences is increased. Thus, if long CAZAC sequence is available,correlation can be reduced and spreading gain can be obtained.

Although the control signal is mapped to the CAZAC sequence by employingthe cyclic shift, this is only illustrative. User equipments areidentified by using different cyclic shifts.

FIG. 12 illustrates a control channel employing CDM (Code DivisionMultiplexing) method. Respective user equipments use control channels towhich different codes are assigned. Specific sequences are separatelyallocated to the control region by each user-equipment. The sequencesare orthogonal to each other.

Referring to FIG. 12, in an upper control region, a control signal isallocated to 6 OFDM symbols with respect to one slot including 8 OFDMsymbols. Reference signals are allocated to remaining 2 OFDM symbols. Ina lower control region, one sequence which is mapped to a control signalis allocated to OFDM symbols in order to apply longer sequence per oneslot.

The size or number of the OFDM symbols to which the reference signal isallocated is illustrative, but not limited to. If channel is estimatedby using the reference signals, gain exists since the number of cyclicshift available to the CAZAC sequence is increased.

The format of the control channel is illustrative. The upper and lowercontrol regions may have the same structure. The format of the controlchannel may be varied depending on time.

When CAZAC sequence is used in order to identify user equipments, theorthogonality between the user equipments has to be maintained byallocating different root indices of the CAZAC sequence to therespective user equipments. Alternatively, the orthogonality between theuser equipments can be maintained by allocating different cyclic shifts.

Various methods may be used in order to transmit a control signal on acontrol channel. A method of directly modulating and transmitting thecontrol signal may be adopted or a method of mapping the control signalto a sequence and sending the sequence may be adopted.

FIG. 13 illustrates an example of a frequency-hopping pattern on asubframe.

Referring to FIG. 13, frequency hopping is performed on control signalsfor two user equipments per OFDM-symbol basis. By performing OFDM symbolbased frequency hopping, time diversity gain can be obtained.

One slot includes eight OFDM symbols. Control signals for two userequipments are alternately allocated to six OFDM symbols. The referencesignals are allocated to two OFDM symbols. The number of the OFDMsymbols included in one slot, and the number or position of the OFDMsymbols used for the reference signals are only illustrative, but notlimited to.

A plurality of OFDM symbols may be used as an unit for performingfrequency hopping. Radio resources defined as the length of an allocatedsequence may be defined as a basic unit.

Not only a frequency diversity gain, but also a time diversity gain canbe obtained by performing a number of frequency hopping on a subframe.

<Transmission of a Control Signal Along with User Data>

Both user data and a control signal are transmitted through a dataregion. In order to multiplex the user data and the control signal, twomethods are possible. The first method is a method of performing DFTspreading both the control signal and the user data and then performingIFFT. The second method is a method of performing DFT spreading only theuser data and then performing IFFT on both the user data and the controlsignal.

FIG. 14 is a block diagram illustrates an example in which user data anda control signal are multiplexed.

Referring to FIG. 14, both user data and a control signal are input to aDFT unit 410 and then undergo DFT. An IFFT unit 420 performs IFFT on theDFT-spreaded data.

FIG. 15 is a block diagram illustrates another example in which userdata and a control signal are multiplexed.

Referring to FIG. 15, user data is input to a DFT unit 510 and thenundergoes DFT. An IFFT unit 520 performs IFFT on a control signal andthe DFT-spreaded user data The control signal can be input to the IFFTunit 520 in a localized form. That is, the control signal can be inputto the IFFT unit 520 so that it occupies localized subcarriers.Alternatively, the control signal can be input to the IFFT unit 520 in adistributed fashion. The control signal can be input to the IFFT unit520 so that it occupies distributed subcarriers.

The method of inserting the control signal before DFT can give good PARand frequency diversity gain since single carrier characteristicmaintains. On the contrary, the method of inserting the control signalafter DFT can give poor PAPR since single carrier characteristic doesnot maintain, but give time diversity gain. When channel condition canaccurately be estimated, coverage can be maximized by obtaining timediversity through good channel.

Meanwhile, when multiplexing a control signal and user data, the controlsignal can be allocated to a control region or a data region.

FIG. 16 illustrates an example in which a control signal is allocated toa control region.

Referring to FIG. 16, when multiplexing a control signal and user data,the control signal is allocated to a control region and the user data isallocated to a data region. This is efficient when the size of thecontrol region is relatively large because the control signal isallocated to only the control region irrespective of whether it ismultiplexed with the user data.

FIG. 17 illustrates an example in which a control signal is allocated toa data region.

Referring to FIG. 17, a data region is divided for a region for acontrol signal and a region for user data in frequency domain. This canachieve simple scheduling and reduce the size of a control region.

Multiplexing of a control signal and user data can adopt frequencydivision multiplexing. That is, the control signal and the user dataallocated to different frequencies within a data region.

FIG. 18 illustrates an example in which a control signal and user dataare time-division multiplexed.

Referring to FIG. 18, a control signal and user data are allocated todifferent radio resources in time domain.

In time division multiplexing or frequency division multiplexing, acontrol signal can be allocated after direct modulation or after beingmapped to a sequence.

When the control signal is mapped to the sequence, it can be transmittedafter performing an operation with user data.

FIG. 19 illustrates multiplexing of a control signal and user datathrough multiplication operation. FIG. 20 illustrates multiplexing of acontrol signal and user data through addition operation.

After a control signal is mapped to a sequence, the sequence can beadded or multiplied to subcarriers to which user data is allocated. Whenthe control signal is multiplied to the user data, the properties of asingle carrier maintains, therefore, relatively low PAPR can beachieved.

The steps of a method described in connection with the embodimentsdisclosed herein may be implemented by hardware, software or acombination thereof. The hardware may be implemented by an applicationspecific integrated circuit (ASIC) that is designed to perform the abovefunction, a digital signal processing (DSP), a programmable logic device(PLD), a field programmable gate array (FPGA), a processor, acontroller, a microprocessor, the other electronic unit, or acombination thereof. A module for performing the above function mayimplement the software. The software may be stored in a memory unit andexecuted by a processor. The memory unit or the processor may employ avariety of means that is well known to those skilled in the art.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims. Therefore, allchanges and modifications that fall within the metes and bounds of theclaims, or equivalence of such metes and bounds are intended to beembraced by the appended claims.

1-10. (canceled)
 11. In a wireless communication system, a method oftransmitting a control signal from user equipment to a base station, themethod comprising: dividing the control signal into a first portion anda second portion; and transmitting the control signal to the basestation, wherein the control signal is transmitted in a subframe, thesubframe comprising a control region and a data region in the frequencydomain, and a first slot and a second slot in the time domain, the firstportion of the control signal occupying a first frequency in the firstslot and the second portion of the control signal occupying a secondfrequency in the second slot.
 12. The method of claim 11, wherein thecontrol region occupies an upper and a lower portion of the subframebandwidth and the data region occupies a portion of the subframebandwidth between the upper and lower portions.
 13. The method of claim12, wherein the frequencies in the data region are between thefrequencies in the upper portion of the control region and lower portionof the control region.
 14. The method of claim 11 further comprising:processing the control sequence by a cycle shifted sequence.
 15. Themethod of claim 14 further comprising: performing an Inverse FastFourier Transform (IFFT) on the processed control signal.
 16. The methodof claim 14, wherein the sequence is a CAZAC sequence.
 17. The method ofclaim 16, wherein the CAZAC sequence is a Zadoff-Chu sequence.
 18. Themethod of claim 11 further comprising: transmitting a control signal foreach of a plurality of user equipment in the subframe.
 19. The method ofclaim 18, wherein a first portion of the control signal for each of theplurality of user equipment occupies a corresponding frequency in thecontrol region in the first slot, wherein the second portion of thecontrol signal for each of the plurality of user equipment occupies acorresponding frequency in the control region in the second slot, andwherein the frequency associated with the first slot and the frequencyassociated with the second slot for each of the plurality of userequipment is at least separated by the frequencies in the data region.20. The method of claim 19, wherein the control signal associated withat least one of the plurality of user equipment occupying a frequency inthe data region.
 21. In a wireless communication system, a method oftransmitting a control signal from user equipment to a base station, themethod comprising: mapping the control signal to a cycle shiftedsequence; performing an Inverse Fast Fourier Transform (IFFT) on themapped control signal; and transmitting the transformed, mapped controlsignal in a subframe, wherein the subframe includes a control region inthe frequency domain, the control region including a first and a secondtime slot in the time domain, and wherein a portion of the controlsignal is transmitted at a first frequency in the first time slot andanother portion of the control signal is transmitted at second,different frequency in the second time slot.
 22. The method of claim 21,wherein the subframe further includes, in the frequency domain, a dataregion separate from the control region.
 23. The method of claim 22,wherein the control region comprises a plurality of higher frequenciesand a plurality of lower frequencies, which are lower than the pluralityof higher frequencies, and wherein the data region comprises a pluralityof frequencies that are lower than the plurality of higher frequenciesin the control region and higher than the plurality of lower frequenciesin the control region.
 24. The method of claim 23, wherein the frequencyused for transmitting the first portion of the control signal in thefirst time slot of the control region and the frequency used fortransmitting the control signal in the second time slot of the controlregion are at least separated by the frequencies in the data region. 25.The method of claim 21, wherein the cyclic shift of the sequenceidentifies the user equipment.
 26. The method of claim 21, wherein thecyclic shift of the sequence identifies the control signal.
 27. Themethod of claim 21, wherein the sequence is a CAZAC sequence.
 28. Themethod of claim 27, wherein the sequence is a Zadoff-Chu sequence. 29.The method of claim 21, wherein at least one of the first and secondtime slots comprises a plurality of single carrier-frequency divisionmultiple access (SC-FDMA) symbols.
 30. The method of claim 29, whereinat least one SC-FDMA symbol is allocated to a reference signal andwherein the remaining SC-FDMA symbols are allocated to the controlsignal.
 31. The method of claim 21, wherein the control signal is anacknowledgement (ACK)/negative-acknowledgement (NACK) signal or achannel quality indicator (CQI).
 32. The method of claim 22 furthercomprising: transmitting a second control signal using a frequency inthe data region.
 33. In a wireless communications system, user equipmentcomprising: a data processing unit configured to map a control signal toa cycle shifted sequence; a modulation unit configured to perform anInverse Fast Fourier Transform (IFFT) on the mapped control signal; anda radio frequency unit and a transmit antenna configured to transmit thetransformed, mapped control signal in a subframe, wherein the subframecomprises a control region in the frequency domain, wherein the controlregion comprises a first slot and a second slot in the time domain, andwherein a portion of the control signal is transmitted at a firstfrequency in the first slot and another portion of the control signal istransmitted at second, different frequency in the second slot.
 34. Themethod of claim 33, wherein the subframe further includes, in thefrequency domain, a data region separate from the control region. 35.The user equipment of claim 34, wherein the control region comprises aplurality of higher frequencies and a plurality of lower frequencies,which are lower than the plurality of higher frequencies, and whereinthe data region comprises a plurality of frequencies that are lower thanthe plurality of higher frequencies in the control region and higherthan the plurality of lower frequencies in the control region.
 36. Theuser equipment of claim 35, wherein the frequency used for transmittingthe first portion of the control signal in the first slot of the controlregion and the frequency used for transmitting the control signal in thesecond slot of the control region are at least separated by thefrequencies in the data region.
 37. The user equipment of claim 33,wherein the cyclic shift of the sequence identifies the user equipment.38. The user equipment of claim 33, wherein the cyclic shift of thesequence identifies the control signal.
 39. The user equipment of claim33, wherein the sequence is a CAZAC sequence.
 40. The user equipment ofclaim 39, wherein the sequence is a Zadoff-Chu sequence.
 41. The userequipment of claim 33, wherein at least one of the first and second timeslots comprises a plurality of single carrier-frequency divisionmultiple access (SC-FDMA) symbols.
 42. The user equipment of claim 31,wherein at least one SC-FDMA symbol is allocated to a reference signaland wherein the remaining SC-FDMA symbols are allocated to the controlsignal.
 43. The user equipment of claim 33, wherein the control signalis an acknowledgement (ACK)/negative-acknowledgement (NACK) signal or achannel quality indicator (CQI).
 44. The user equipment of claim 34,wherein the radio frequency unit and the transmit antenna are furtherconfigured to transmit a second control signal using a frequency in thedata region.